This invention is a rotary machine for treating work surfaces in corners, the effects being to remove the surface, clean, polish or anneal.
Rotary drum surface scrapers and the like are ineffectual in biplaner intersections, and even more ineffectual in triplaner intersections. Wire brushes deform, but when forced into corners with the axis of rotation approaching the corner fail to reach into the corner and aggrevate performance by over-abrading. These same brushes do not guarantee intimate contact of the scraping elements with the intersection when used with the rotational plane of the brush parallel to one side of the biplaner corner. Thus, treatment of corners, biplaner and triplaner, is usually left to non-powered hand tools.
Existing tools have not provided convenient cleaning of window mullions or floor corners, necessitating hand treatment. Especially, existing tools have not provided protection against damaging one surface of a biplaner corner while treating the second surface fully up to the intersection.
Many rasps and other drum type scrapers will load up with the material being removed, and must be periodically cleaned to restore the cutting effect. The invention, being of bird-cage design, allows the removed material to fall free of the scraping elements and be swept away by the action of the blades.